Socket for fluorescent lamps



Oct. 30, 1956 G. N. FORTIN SOCKET FOR FLUORESCENT LAMPS Filed Nov. 18. 1952 A TTOR NE YS.

United States* PatentO sooner Fon FLUoREscEN'rLAMPs George N. l'iortin, Pawtucket, R. I. s `Application November 1s, 1952, senat No; 321,155

` Y s claims. (Cl. ass-se) My invention relates to sockets for `fluorescent lamps having two contact pins and of the type now in commercial 1 use.

In fluorescent lamp sockets now in `general use entrance slotsl for the contact prongs of the liuorescent lamp are generally provided in the lower edge of the lamp socket opening when the lamp socket is mounted. Particularly in industrial installation this type of socket has not proved to be' very practical since in this type of `installation there is considerable vibration present which tends to dislodge the fluorescent lamp from itssocket. This is generally due to the fact that through aging, the contact springs lose their resilience, and eventually vibration dislodges the lamp from the socket, causing it to fall, the prongs readily passing out of the slots that in these prior art sockets generally extend in a downward direction in the socket. To combat this ditculty, variousretainer means have been utilized, the most common form of which slips over the end ofthe lamp socket and closes the slot Ato prevent the lamp from falling out.`

It is,- therefore, the main object of my invention to provide alluorescent lampsocketwhich will overcome the foregoing difficulties.

Another object of my invention is to provide a fluorescent lamp socket which will not need any external means to hold the iluorescent lamp in the socket.

A further object of my invention is to provide a fluorescent lamp socket of such a construction that should the iiuorescent lamp contact pins'be dislodged from the spring contact means in the socket, the lamp will remain engaged with the insulating portion of the socket.

A still further object of my invention is the provision of a uorescent lamp socket which comprises relatively few parts such that it may be easily assembled and manufactured at low cost.

In the drawings:

Figure l is a plan view of a tubular discharge lamp supported at each end by lamp sockets constructed in accordance with my invention;

Figure 2 is a front elevation of the lamp socket;

Figure 3 is a rear elevation thereof with the closure plate removed, showing the contact arrangement;

Figure 4 is a sectional view along lines 4--4 of Figure 2, showing the lamp pins in position;

Figure 5 is an edge view taken on lines 5-5 of Figure 2;

Figure 6 is a sectional view taken on lines 6--6 of Figure 3;

Figure 7 is a sectional view taken on lines 7-7 of Figure 3;

Figure 8 is a rear elevational view of the lamp socket with the contact elements removed;

Figures 9 and 10 are perspective views of the contact strips.

In proceeding with my invention, I provide a left and a right housing of insulating material such as molded plastic, cover plates, and two pairs of contact strips. The general shape of the housing is shown by the drawings, the

2,769,152 Patented Oct. 30, 1956 rCe 2 housing being formed with an upright portion extending from a base portion, the base portion serving to mount the socket on a supporting plate such as a reflector in a manner well known to those skilled in the art so that the upright portion will be suspended from the reector.

Referring to the drawings, I have shown a tubular discharge lamp 11 supported at each end by lamp sockets 12. The lamp 11 may be of a type commonly known to the trade as a fluorescent lamp, in which the filaments are mounted at each end. Electrical connection to the filaments is obtained through spaced contact pins 13, which are mounted in opposite ends of the lamp and which project therefrom, thereby serving as a mounting means. The lamp socket `12 is made up of an upright member 14 and base member l15. The upright member 14 has side walls 14 and an end wall 14" and is provided with a U-shaped recess 16 and a slot 17 communicating there-` with. Spring receiving channels 16 extend from the recess 16 separatedfby a raised portion 18 formed integral with the upright member 14 and the base 15. The upper end of this raised portion 18 is provided with a narrowneck 19, which supports a generally circular guide portion 20 having a diameter of approximately the contact pin spacing of the fluorescent lamp 11.

Disposed `in each channel 16 are resilient contact strips 21 and 22. Each of the contact strips 21 and 22 is resilient and provided with an arcuate upper portion 23 and may also be provided with small depressions 24 to engage the contact pins 13 of the fluorescent lamp 11. Contact strip 22 is additionally provided with an up-tulrned end 25 to assist sliding the contact pin 13 into the depression and contact strip 21 is provided with an extended end closely adjacent but spaced from neck 19 to prevent the contact pind13 from slipping to the Wrong side of the contact. Each of the contact` strips 21 and 22 has a horizontal end 26 which `serves as a terminal portion and. which is seated in the slots 27, 28 molded into the wall and center portion, respectively. To additionally hold the contact springs in position in the leg portions of the channels 16 a horizontal partition 29 integral with the socket 12 extends from each side wall to within a short distance of the center portion 18. These partitions being placed a predetermined distance from the base form guides for the contact springs 21 and 22, respectively. Each of `the horizontal portions 26 of the contact members is provided with a hole 30 to accept a terminal screw, not shown, for the attachment of an electric conductor. To further hold the contact springs in the channels 16', there is additionally provided an insulating plate 31 which is suitably fastened to the back of the upright member by rivets 32 forming a rear wall.

The base 15 which is integral with the upright portion 14 is provided with parallel horizontal slots 33 which provide ducts for the electrical conductors that lead to the terminal portions 26 of the contact strips. A vertical slot 35 is positioned in the center of the base 15 for the reception of an attaching bolt. Positioned along this vertical slot 35 is a groove 36 of a thickness to receive an attaching nut which may be readily slipped therein, the attaching bolt communicating with the threads in this attaching nut and holding the base 15 to the reilector of the uorescent lamp fixture. To insulate the terminals from the reflector of the fluorescent lamp ixture, a tiber insulating strip, not shown, may be seated in the recesses 37 which are provided in either end of the face.

In mounting a lamp, a pair of sockets is provided, one for each end of the lamp, and these are suspended from a support such as a reflector so that the slots 17 will open in the same direction. The lamp contact prongs 13 are moved horizontally through the slots 17 until one of the contact prongs engages the contact member 21 and rests against the neck portion 19. By merely rotating the lamp, the other contact prong will swing around the first contact prong and engage the spring contact member 22, sliding therealong until the depression 24 is reached. To release the lamp, it is merely necessary to reverse'the process, inasmuch as the edges of the depressions 24 and the contact spring member 22 are sufliciently'roundedA to permit the contact p'rongs.13 toslip out thereof. Ad ditionally, theY lamp maybe inserted in the socket by passing the prongs 13 through the slot 17 and directing one set ofprongs upwardly to engage the up-turned portion; 25 of the contact spring member 22. The lamp 11 may then be slightly rotated and' moved laterally to position the two prongs vertically and in contact with the contact spring members 21 and 22 at the depressions V24 thereof.

It will be seen that by shaping the recess 16 in the manner shown and by providing the entrance slot 17 in the side wall of the lamp socket, accidental removal of the .lamp from the socket is practically prevented. Should for instance the Contact pin 13A become disengaged With the contact spring 21 andV the other pin 13 disengaged with the contact spring 22,V theV lamp pins will remain retained in the recess 16 and cannot pass out of the slot 17' to cause the lamp to fall from the socketbecause of its distance above the bottom ofthe recess 16 being greater than the spacingbetween contact pins 13. Additionally, it will be noted thatthe Contact pins 13 are disposed in a vertical plane and are urged Vagainst the central raised portion 20. In this manner vibration,- which normally occurs in a vertical plane, will be partially absorbed by the resilience of the contact springs 21 and 22, thereby further preventing the lamp from being dislodged from the socket.

My invention provides a rugged socket construction for supporting a tubular lamp, which is particularly adapted to industrial installation although it obviously has general utility for use in all applications. The contacts are so arranged that the lamp is held securely in' position in the lamp socket housing and excellent electrical contact is maintained between the lamp contacts and those of the lamp holder. Further, it is a relatively simple matter to mount the lamp in the socket, since the lamp prongs are merely moved transversely into the recess and given a turn to lock the lamp in position.

Certainmodictions can obviously be made in the construction` shown, particularly in making the socket broadly universal.` For instance, the base could extend in both directions from the vertical member 1'4 and the face of the vertical member altered to provide a through recess. Two cover plates would then be provided, one carrying the raised portions 18, 19, 20 and suitable openings for the contact prongs, andthe other identical to plate 31. These plates wouldnt into suitable ledges formed in member 14ar1'd be faS'teied'tOgthe 'to firi hnitary structure. v

I claim:

1. A socketfor fluorescent lamps having'spaced contact pins comprising a bodyY of insulating material having a generally arcuate recess, the center of said arcuate recess having an arcuate guide portion of a diameter equal to the spacing of said pins, a slot opening through a side wall of said body into said recess in line with a tangent of said guide portion remote from the end wall'of said body, said tangent forming substantially a rightangle with said side wall, and contact springs in said recess for detachably engaging said prongs.

2. In a socket for iluorescent lamps-asin claim 1 whered in two channels lead from said arcuate'A recess, said chanV nels having means therein tofh'old said contact springs in said body.

3. In 'a socketforr uorescent lamps as in claim t wherein said` arcuate" recess is a C-shaped recess.

References Cited in the ijle of this patent UNITED STATES PATENTS 

